These days, for the safety of the passengers, most vehicles are equipped with airbags inside the vehicles. The airbags are connected with an inflator and several detectors. When any one of the detectors detects an impact against the vehicle, the inflator instantly generates a large amount of gas to the airbags so that the airbags are inflated instantly to prevent the head and chest of the passengers from colliding with the hard objects in the vehicle to achieve the purpose of protecting the passengers.
Although the above-mentioned airbags can protect the safety of the passengers, the inventor observes that if the vehicle is rolling during the accident, the airbags are not fixed to the vehicle after being inflated and the airbags will deflate slowly. The passengers may be thrown out of the vehicle due to violent shaking and the centrifugal force caused by the rolling of the vehicle, resulting in serious casualties. Five-point seat belts are developed for effectively retaining the passengers on the seats, but the five-point seat belt is very complicated for use and costly. Therefore, it is only used to racing cars or sports cars. It is not widely used to general vehicles. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.